1. AWADH ALQAHTANI MD,MSC,FRCSC(SURGERY)FRCSC(ONCOLOGY)FISC SURGICAL ONCOLOGIST AND LAPAROSCOPIC BARIATRIC SURGEON 29/09/2013 SHOCK & METABOLIC RESPONSE

2. OBJECTIVES Definition Approach to the hypotensive patient Types Specific treatments

3. DEFINITION OF SHOCK Inadequate oxygen delivery to meet metabolic demands Results in global tissue hypoperfusion and metabolic acidosis Shock can occur with a normal blood pressure and hypotension can occur without shock

4. UNDERSTANDING SHOCK Inadequate systemic oxygen delivery activates autonomic responses to maintain systemic oxygen delivery Sympathetic nervous system NE, epinephrine, dopamine, and cortisol release Causes vasoconstriction, increase in HR, and increase of cardiac contractility (cardiac output) Renin-angiotensin axis Water and sodium conservation and vasoconstriction Increase in blood volume and blood pressure

5. UNDERSTANDING SHOCK Cellular responses to decreased systemic oxygen delivery ATP depletion → ion pump dysfunction Cellular edema Hydrolysis of cellular membranes and cellular death Goal is to maintain cerebral and cardiac perfusion Vasoconstriction of splanchnic, musculoskeletal, and renal blood flow Leads to systemic metabolic lactic acidosis that overcomes the body’s compensatory mechanisms

6. GLOBAL TISSUE HYPOXIA Endothelial inflammation and disruption Inability of O2 delivery to meet demand Result: Lactic acidosis Cardiovascular insufficiency Increased metabolic demands

7. MULTIORGAN DYSFUNCTION SYNDROME (MODS) Progression of physiologic effects as shock ensues Cardiac depression Respiratory distress Renal failure DIC Result is end organ failure

8. PATHOPHYSIOLOGY

9. APPROACH TO THE PATIENT IN SHOCK ABCs Cardiorespiratory monitor Pulse oximetry Supplemental oxygen IV access ABG, labs Foley catheter Vital signs including rectal temperature

10. DIAGNOSIS Physical exam (VS, mental status, skin color, temperature, pulses, etc) Infectious source Labs: CBC Chemistries Lactate Coagulation studies Cultures ABG

11. FURTHER EVALUATION CT of head/sinuses Lumbar puncture Wound cultures Acute abdominal series Abdominal/pelvic CT or US Cortisol level Fibrinogen, FDPs, D-dimer

12. APPROACH TO THE PATIENT IN SHOCK History Recent illness Fever Chest pain, SOB Abdominal pain Comorbidities Medications Toxins/Ingestions Recent hospitalization or surgery Baseline mental status Physical examination Vital Signs CNS – mental status Skin – color, temp, rashes, sores CV – JVD, heart sounds Resp – lung sounds, RR, oxygen sat, ABG GI – abd pain, rigidity, guarding, rebound Renal – urine output

13. IS THIS PATIENT IN SHOCK? Patient looks ill Altered mental status Skin cool and mottled or hot and flushed Weak or absent peripheral pulses SBP <110 Tachycardia Yes! These are all signs and symptoms of shock

14. SHOCK Do you remember how to quickly estimate blood pressure by pulse? 60 80 70 90 If you palpate a pulse, you know SBP is at least this number

15. GOALS OF TREATMENT ABCDE Airway control work of Breathing optimize Circulation assure adequate oxygen Delivery achieve End points of resuscitation

16. AIRWAY Determine need for intubation but remember: intubation can worsen hypotension Sedatives can lower blood pressure Positive pressure ventilation decreases preload May need volume resuscitation prior to intubation to avoid hemodynamic collapse

17. CONTROL WORK OF BREATHING Respiratory muscles consume a significant amount of oxygen Tachypnea can contribute to lactic acidosis Mechanical ventilation and sedation decrease WOB and improves survival

18. OPTIMIZING CIRCULATION Isotonic crystalloids Titrated to: CVP 8-12 mm Hg Urine output 0.5 ml/kg/hr (30 ml/hr) Improving heart rate May require 4-6 L of fluids No outcome benefit from colloids

19. MAINTAINING OXYGEN DELIVERY Decrease oxygen demands Provide analgesia and anxiolytics to relax muscles and avoid shivering Maintain arterial oxygen saturation/content Give supplemental oxygen Maintain Hemoglobin > 10 g/dL Serial lactate levels or central venous oxygen saturations to assess tissue oxygen extraction

20. END POINTS OF RESUSCITATION Goal of resuscitation is to maximize survival and minimize morbidity Use objective hemodynamic and physiologic values to guide therapy Goal directed approach Urine output > 0.5 mL/kg/hr CVP 8-12 mmHg MAP 65 to 90 mmHg Central venous oxygen concentration > 70%

21. PERSISTENT HYPOTENSION Inadequate volume resuscitation Pneumothorax Cardiac tamponade Hidden bleeding Adrenal insufficiency Medication allergy

22. TYPES OF SHOCK Hypovolemic Septic Cardiogenic Anaphylactic Neurogenic Obstructive

23. CAUSES OF SHOCK

24. THE PROGRESSION OF SHOCK Signs and symptoms

25. WHAT TYPE OF SHOCK IS THIS? 68 yo M with hx of HTN and DM presents to the ER with abrupt onset of diffuse abdominal pain with radiation to his low back. The pt is hypotensive, tachycardic, afebrile, with cool but dry skin Types of Shock Hypovolemic Septic Cardiogenic Anaphylactic Neurogenic Obstructive Hypovolemic Shock

26. HYPOVOLEMIC SHOCK

27. Non-hemorrhagic Vomiting Diarrhea Bowel obstruction, pancreatitis Burns Neglect, environmental (dehydration) Hemorrhagic GI bleed Trauma Massive hemoptysis AAA rupture Ectopic pregnancy, post-partum bleeding

28. HYPOVOLEMIC SHOCK ABCs Establish 2 large bore IVs or a central line Crystalloids Normal Saline or Lactate Ringers Up to 3 liters PRBCs O negative or cross matched Control any bleeding Arrange definitive treatment

29. EVALUATION OF HYPOVOLEMIC SHOCK CBC ABG/lactate Electrolytes BUN, Creatinine Coagulation studies Type and cross-match As indicated CXR Pelvic x-ray Abd/pelvis CT Chest CT GI endoscopy Bronchoscopy Vascular radiology

30. WHAT TYPE OF SHOCK IS THIS? An 81 yo F resident of a nursing home presents to the ED with altered mental status. She is febrile to 39.4, hypotensive with a widened pulse pressure, tachycardic, with warm extremities Types of Shock Hypovolemic Septic Cardiogenic Anaphylactic Neurogenic Obstructive Septic

31. SEPSIS Two or more of SIRS criteria Temp > 38 or < 36 C HR > 90 RR > 20 WBC > 12,000 or < 4,000 Plus the presumed existence of infection Blood pressure can be normal!

32. SEPTIC SHOCK Sepsis (remember definition?) Plus refractory hypotension After bolus of 20-40 mL/Kg patient still has one of the following: SBP < 90 mm Hg MAP < 65 mm Hg Decrease of 40 mm Hg from baseline

33. PATHOGENESIS OF SEPSIS Nguyen H et al. Severe Sepsis and Septic-Shock: Review of the Literature and Emergency Department Management Guidelines. Ann Emerg Med. 2006;42:28-54.

34. SEPTIC SHOCK Clinical signs: Hyperthermia or hypothermia Tachycardia Wide pulse pressure Low blood pressure (SBP<90) Mental status changes Beware of compensated shock! Blood pressure may be “normal”

35. ANCILLARY STUDIES Cardiac monitor Pulse oximetry CBC, Chem 7, coags, LFTs, lipase, UA ABG with lactate Blood culture x 2, urine culture CXR Foley catheter (why do you need this?)

36. TREATMENT OF SEPTIC SHOCK 2 large bore IVs NS IVF bolus- 1-2 L wide open (if no contraindications) Supplemental oxygen Empiric antibiotics, based on suspected source, as soon as possible

37. TREATMENT OF SEPSIS Antibiotics- Survival correlates with how quickly the correct drug was given Cover gram positive and gram negative bacteria Zosyn 3.375 grams IV and ceftriaxone 1 gram IV or Imipenem 1 gram IV Add additional coverage as indicated Pseudomonas- Gentamicin or Cefepime MRSA- Vancomycin Intra-abdominal or head/neck anaerobic infections- Clindamycin or Metronidazole Asplenic- Ceftriaxone for N. meningitidis, H. infuenzae Neutropenic – Cefepime or Imipenem

38. PERSISTENT HYPOTENSION If no response after 2-3 L IVF, start a vasopressor (norepinephrine, dopamine, etc) and titrate to effect Goal: MAP > 60 Consider adrenal insufficiency: hydrocortisone 100 mg IV

39. WHAT TYPE OF SHOCK IS THIS? A 55 yo M with hx of HTN, DM presents with “crushing” substernal CP, diaphoresis, hypotension, tachycardia and cool, clammy extremities Types of Shock Hypovolemic Septic Cardiogenic Anaphylactic Neurogenic Obstructive Cardiogenic

40. CARDIOGENIC SHOCK

41. Signs: Cool, mottled skin Tachypnea Hypotension Altered mental status Narrowed pulse pressure Rales, murmur Defined as: SBP < 90 mmHg CI < 2.2 L/m/m 2 PCWP > 18 mmHg

42. ETIOLOGIES What are some causes of cardiogenic shock? AMI Sepsis Myocarditis Myocardial contusion Aortic or mitral stenosis, HCM Acute aortic insufficiency

43. PATHOPHYSIOLOGY OF CARDIOGENIC SHOCK Often after ischemia, loss of LV function Lose 40% of LV clinical shock ensues CO reduction = lactic acidosis, hypoxia Stroke volume is reduced Tachycardia develops as compensation Ischemia and infarction worsens

44. ANCILLARY TESTS EKG CXR CBC, Chem 10, cardiac enzymes, coagulation studies Echocardiogram

45. TREATMENT OF CARDIOGENIC SHOCK Goals- Airway stability and improving myocardial pump function Cardiac monitor, pulse oximetry Supplemental oxygen, IV access Intubation will decrease preload and result in hypotension Be prepared to give fluid bolus

46. TREATMENT OF CARDIOGENIC SHOCK AMI Aspirin, beta blocker, morphine, heparin If no pulmonary edema, IV fluid challenge If pulmonary edema Dopamine – will ↑ HR and thus cardiac work Dobutamine – May drop blood pressure Combination therapy may be more effective PCI or thrombolytics RV infarct Fluids and Dobutamine (no NTG) Acute mitral regurgitation or VSD Pressors (Dobutamine and Nitroprusside)

47. WHAT TYPE OF SHOCK IS THIS? A 34 yo F presents to the ER after dining at a restaurant where shortly after eating the first few bites of her meal, became anxious, diaphoretic, began wheezing, noted diffuse pruritic rash, nausea, and a sensation of her “throat closing off”. She is currently hypotensive, tachycardic and ill appearing. Types of Shock Hypovolemic Septic Cardiogenic Anaphylactic Neurogenic Obstructive Anaphalactic

48. ANAPHYLACTIC SHOCK Anaphylaxis – a severe systemic hypersensitivity reaction characterized by multisystem involvement IgE mediated

49. ANAPHYLACTIC SHOCK What are some symptoms of anaphylaxis? First- Pruritus, flushing, urticaria appear Next- Throat fullness, anxiety, chest tightness, shortness of breath and lightheadedness Finally- Altered mental status, respiratory distress and circulatory collapse

50. ANAPHYLACTIC SHOCK- DIAGNOSIS Clinical diagnosis Defined by airway compromise, hypotension, or involvement of cutaneous, respiratory, or GI systems Look for exposure to drug, food, or insect Labs have no role

51. ANAPHYLACTIC SHOCK- TREATMENT ABC’s Angioedema and respiratory compromise require immediate intubation IV, cardiac monitor, pulse oximetry IVFs, oxygen Epinephrine Second line Corticosteriods H1 and H2 blockers

52. ANAPHYLACTIC SHOCK- TREATMENT Epinephrine 0.3 mg IM of 1:1000 (epi-pen) Repeat every 5-10 min as needed Caution with patients taking beta blockers- can cause severe hypertension due to unopposed alpha stimulation For CV collapse, 1 mg IV of 1:10,000 If refractory, start IV drip

53. ANAPHYLACTIC SHOCK - TREATMENT Corticosteroids Methylprednisolone 125 mg IV Prednisone 60 mg PO Antihistamines H1 blocker- Diphenhydramine 25-50 mg IV H2 blocker- Ranitidine 50 mg IV Bronchodilators Albuterol nebulizer Atrovent nebulizer Magnesium sulfate 2 g IV over 20 minutes Glucagon For patients taking beta blockers and with refractory hypotension 1 mg IV q5 minutes until hypotension resolves

54. WHAT TYPE OF SHOCK IS THIS? A 41 yo M presents to the ER after an MVC complaining of decreased sensation below his waist and is now hypotensive, bradycardic, with warm extremities Types of Shock Hypovolemic Septic Cardiogenic Anaphylactic Neurogenic Obstructive Neurogenic

55. NEUROGENIC SHOCK

56. Occurs after acute spinal cord injury Sympathetic outflow is disrupted leaving unopposed vagal tone Results in hypotension and bradycardia

57. NEUROGENIC SHOCK Loss of sympathetic tone results in warm and dry skin Shock usually lasts from 1 to 3 weeks Any injury above T1 can disrupt the entire sympathetic system Higher injuries = worse paralysis

58. NEUROGENIC SHOCK- TREATMENT A,B,Cs Remember c-spine precautions Fluid resuscitation Keep MAP at 85-90 mm Hg for first 7 days Thought to minimize secondary cord injury If crystalloid is insufficient use vasopressors Search for other causes of hypotension For bradycardia Atropine Pacemaker

59. NEUROGENIC SHOCK- TREATMENT Methylprednisolone Used only for blunt spinal cord injury High dose therapy for 23 hours Must be started within 8 hours Controversial- Risk for infection, GI bleed

60. WHAT TYPE OF SHOCK IS THIS? A 24 yo M presents to the ED after an MVC c/o chest pain and difficulty breathing. On PE, you note the pt to be tachycardic, hypotensive, hypoxic, and with decreased breath sounds on left Types of Shock Hypovolemic Septic Cardiogenic Anaphylactic Neurogenic Obstructive

61. OBSTRUCTIVE SHOCK

62. Tension pneumothorax Air trapped in pleural space with 1 way valve, air/pressure builds up Mediastinum shifted impeding venous return Chest pain, SOB, decreased breath sounds No tests needed! Rx: Needle decompression, chest tube

63. OBSTRUCTIVE SHOCK Cardiac tamponade Blood in pericardial sac prevents venous return to and contraction of heart Related to trauma, pericarditis, MI Beck’s triad: hypotension, muffled heart sounds, JVD Diagnosis: large heart CXR, echo Rx: Pericardiocentisis

64. OBSTRUCTIVE SHOCK Pulmonary embolism Virscow triad: hypercoaguable, venous injury, venostasis Signs: Tachypnea, tachycardia, hypoxia Low risk: D-dimer Higher risk: CT chest or VQ scan Rx: Heparin, consider thrombolytics

65. OBSTRUCTIVE SHOCK Aortic stenosis Resistance to systolic ejection causes decreased cardiac function Chest pain with syncope Systolic ejection murmur Diagnosed with echo Vasodilators (NTG) will drop pressure! Rx: Valve surgery

66. REVIEW 1.The term “shock” is MOST accurately defined as: A.a decreased supply of oxygen to the brain. B.cardiovascular collapse leading to inadequate perfusion. C.decreased circulation of blood within the venous circulation. D.decreased function of the respiratory system leading to hypoxia.

67. REVIEW 3.Signs of compensated shock include all of the following, EXCEPT: A.restlessness or anxiety. B.pale, cool, clammy skin. C.a feeling of impending doom. D.weak or absent peripheral pulses.

68. REVIEW 6.A 60-year-old woman presents with a BP of 80/60 mm Hg, a pulse rate of 110 beats/min, mottled skin, and a temperature of 103.9°F. She is MOST likely experiencing: A.septic shock. B.neurogenic shock. C.profound heart failure. D.a severe viral infection.

69. ANY QUESTIONS? THE END